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g³ - Green Gas for Grid
SF6 alternative for high voltage applications above 66 kV

g³ - green gas for grid - is GE‘s replacement for SF6 gas developed in collaboration with 3M. g³ is a proven and ready-to-go alternative insulating gas mixture for high voltage (HV) electrical transmission equipment, which provides the same technical performance as SF6 in an environmentally friendly way – the impact of g³ is a whopping 98% to 99% less than SF6 gas.

The g³ gas offers an efficient combination of low global warming potential (GWP) with high dielectric performance and extended operating temperatures in accordance with the typical Transmission System Operators’ (TSO) needs.

Sulfur-hexafluoride (SF6) is used in the HV electrical transmission industry because it is an excellent gaseous dielectric medium. Unfortunately, it is also the greenhouse gas with the largest global warming potential (23,500 times more than C02). Much effort has been made across the industry in the last decades to find a viable alternative gas. With g³, a replacement is found in fluoronitrile versus sf6.

g³ is fully type-tested and available for 72.5 kV, 145 kV and 170 kV GIS, GIL up to 420kV and AIS current transformers up to 245 kV.

GE Advantage
Key Benefits
Technical Performance



g³ is an environmentally friendly alternative to SF6 that provides a number of technical, environmental and financial advantages.

  • g³ is fully type-tested and commercially available for GIS up to 145 kV, GIL up to 420kV and AIS current transformers up to 245 kV.
  • g³ is applicable in the same environmental conditions and at the same ambient temperature ranges as SF6.
  • g³ high voltage equipment feature the same dimensional footprint as state-of the-art SF6 equipment.
  • g³ is non toxic and falls in the same safety class as SF6.
  • Global Warming Potential represents only 1 to 2 % of that of SF6.
  • Replacing 1kg of SF6 with g³ is equivalent to saving 16 cars running one year. The potential for global warming reduction is further underscored when you look at the sheer quantity of SF6 installed worldwide. 10,000 tons of SF6 are installed each year, with 80% concentrated in the transmission industry
  • Utilities can qualify for tax reductions or incentives related to greenhouse gas emissions reduction.


g³ is a fully type-tested gas mixture that provides the same technical performance as SF6, while reducing the environmental impact by 98%.

  • Dielectric Withstand: 100% that of SF6. g³ can achive 100% of SF6 performance, under the same ambient conditions and down to -25℃ for GIS or -30℃ for AIS
  • Breaking Performance : Suitable for circuit breakers. g³ has demonstrated breaking capabilities up to 420 kV. The dimensions and the operating energy are similar to that of SF6 equipment.
  • Switching Bus-Transfer Current : Suitable for GIS disconnectors. The gas mixture has a good switching bus-transfer current capability and can be used as a substitute for SF6 for this application.
  • Compliant with T&D Europe guide for validation of SF6 alternative gas

  • 98% to 99% less impact on GWP than SF6
  • No impact on ozone depletion
  • In the same toxicity class as SF6 in its fresh state or after interruption in a circuit breaker
  • Non flammable and avoid risk of soil pollution
  • 3M Novec 4710 molecule is registered in accordance with European REACH process for chemicals

  • g³ supply, g³ handling and g³ monitoring solutions are available with our partners
  • Gas mixtures prepared in factories by certified suppliers
  • g³ filling at customer sites with gas cart
  • Accessories for HV equipment including density switches, valves, moisture absorber
  • Measurement devices to monitor gas ratio, moisture, tightness and detect leakage

Green Gas for Grid Videos

This collection of videos and industry expert talks explores SF6-free insulating gas for HV switchgear and the impacts on the environment between various mixtures including SF6 versus g3. Discover what GE’s g3 replacement for SF6 gas means for HV equipment, and how this SF6 free gas is already type-tested and available for GIS up to 145 kV, GIL up to 420kV, AIS current transformers up to 245 kV.